A preservative for polycarboxylate water-reducing agent containing organic bromine and a preparation method thereof

Abstract

The application belongs to the field of building materials, and particularly relates to a preservative for polycarboxylate water reducing agent containing organic bromine and a preparation method thereof. According to weight parts, the preservative for polycarboxylate water reducing agent contains the following raw materials: 1-15 parts of preservative monomer, 0.5-2.0 parts of bactericidal monomer, 1-2 parts of stabilizer and 50-90 parts of water, wherein the bactericidal monomer is modified isothiazolinone, and the preservative monomer is organic bromine. The application provides a preservative for polycarboxylate water reducing agent which is combined with organic bromine and bactericidal monomer, has strong antibacterial performance, good solubility, is suitable for a concrete water reducing agent system, and has a wide application range and superior performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building materials, and in particular to a preservative for polycarboxylate superplasticizer containing organic bromine and a preparation method thereof. BACKGROUND

[0002] Currently, polycarboxylate superplasticizers often need to add a certain amount of preservatives to extend their service life and stability during use. However, the preservatives in the prior art have the following defects: (1) harmful substance release: some traditional preservatives contain harmful substances such as formaldehyde, benzene and other volatile organic compounds, which may be released into the environment, posing potential risks to human health. (2) reducing water-reducing effect: certain preservatives may interact with polycarboxylate molecules at high concentrations, resulting in impaired performance of the superplasticizer and reduced water-reducing effect. (3) impact on cement gel: some preservatives may react with cement gel, causing the hardening speed of cement to slow down or the setting time to extend, affecting the workability of concrete. (4) environmental pollution: certain preservatives may produce pollutants during production and use, causing negative impacts on the environment.

[0003] In view of the defects of polycarboxylate superplasticizers when using preservatives, some improvement measures have been taken: (1) using environmentally friendly inorganic salts or organic substances as alternative preservatives, which are safer and do not produce harmful volatile organic compounds. For example, some studies have proposed using potassium chloride or other harmless salts as preservatives for polycarboxylate superplasticizers. (2) improving the structure and synthesis method of polycarboxylate molecules to improve the compatibility between the superplasticizer and the preservative and reduce their interaction. For example, some studies have improved the interaction between polycarboxylate molecules and preservatives by adjusting the side chain structure and length of polycarboxylate molecules, thereby improving the water-reducing effect. (3) finding preservatives that do not have adverse reactions with cement gel. For example, some studies have shown that using specific organic acid preservatives such as benzoic acid, propionic acid, etc. can reduce their impact on cement gel. (4) when selecting preservatives, more attention is paid to environmental friendliness and sustainability. For example, preservatives with good biodegradability and less impact on the environment are selected. In addition, by improving the production process, harmful substance emissions are reduced or avoided to reduce environmental pollution.

[0004] Therefore, there is a need for more environmentally friendly preservatives in the future. SUMMARY

[0005] To solve the problems raised in the background art, the present application provides a preservative for polycarboxylate superplasticizer containing organic bromine and a preparation method thereof.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A kind of polycarboxylic acid water-reducing agent containing organic bromine preservative, by weight parts, including the following raw materials: 1~15 parts of preservative monomer, 0.5~2.0 parts of bactericidal monomer, 1~2 parts of stabilizer and 50~90 parts of water, the bactericidal monomer is modified isothiazolinone, the preservative monomer is organic bromine class, its structural formula is as follows:

[0008]

[0009] Wherein M is One of them.

[0010] Preferably, the stabilizer is at least one of propylene glycol, propylene glycol fatty acid ester, D-mannitol, propylene glycol alginate, chitin or polyglycerol ricinoleate.

[0011] Preferably, the preparation method of the modified isothiazolinone, by weight parts, includes the following steps:

[0012] Step (1), 4~6 parts of isothiazolinone compound, 5~7 parts of acid anhydride are added to a four-necked flask with stirring device, thermometer and condenser, 100~180 parts of dimethylbenzene are put in under nitrogen protection, slowly heated, and reacted for 6~8 h to obtain a crude product;

[0013] Step (2), the obtained crude product is ground and washed with 30~50 parts of dimethylbenzene for 3~5 times,

[0014] Vacuum drying to obtain modified isothiazolinone.

[0015] Preferably, the structural formula of the isothiazolinone is as follows:

[0016]

[0017] Wherein R is one of H, Ph, Bn, Et, Me.

[0018] Preferably, the acid anhydride is any one of maleic anhydride, phthalic anhydride, oxalic anhydride.

[0019] Preferably, the slow heating in step (1) is to 100~150 DEG C.

[0020] Preferably, the vacuum drying time in step (2) is 18~36 h.

[0021] A kind of polycarboxylic acid water-reducing agent containing organic bromine preservative preparation method, by weight parts, including the following steps:

[0022] Step (1), the preservative monomer and bactericidal monomer are added to 10~30 parts by weight of water, stirred uniformly to obtain a mixture;

[0023] Step (2), adding the stabilizer to the mixture, adding the remaining water, stirring for 10-30

[0024] min, to obtain the preservative for polycarboxylate water reducing agent.

[0025] The beneficial effects of the present application are:

[0026] (1) The present application uses organic bromine substances as preservative monomers, which are hydrolyzed in water to release HO-Br, which can form a relatively stable hydrogen halide bond with microorganisms, preventing the erosion of mold and other microorganisms under complex environmental conditions, and preventing the sample from being moldy and deteriorated.

[0027] (2) The bactericidal monomer prepared in the present application introduces carboxyl groups on the isothiazolinone molecular structure through N substitution and dehydration of isothiazolinone molecules with anhydride, which enhances the binding degree between molecules, has good water solubility, increases the bacteriostatic activity of the prepared preservative, and improves the solubility, thereby improving the preservative and bactericidal effect of the preservative.

[0028] (3) The present application uses organic bromine and bactericidal monomers as preservative active components, which are suitable for concrete water reducing agent system, enhance the antimicrobial effect, expand the range of microbial growth inhibition, and enhance the drug resistance of the preservative.

[0029] (4) The preservative for polycarboxylate water reducing agent prepared in the present application has strong practicality. DETAILED DESCRIPTION

[0030] Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application, and are not intended to limit the protection scope of the present application.

[0031] Example 1:

[0032] (1) Preparation of bactericidal monomer: 4 parts of benzisothiazolinone and 5 parts of maleic anhydride were added to a four-mouthed baking pan with stirring device, thermometer and condenser under nitrogen protection, 100 parts of dimethylbenzene was slowly heated to 120℃, and reacted for 6h to obtain the crude product. The obtained crude product was ground and washed with 30 parts of dimethylbenzene for 4 times, and vacuum dried for 24h to obtain the reaction product.

[0033] (2) Preparation of preservative for polycarboxylate water reducing agent: 1 part of preservative monomer and 0.5 parts of bactericidal monomer were weighed and added to 20 parts of water, stirred uniformly, then 1 part of propylene glycol and 50 parts of water were added and stirred for 20min to obtain the preservative for polycarboxylate water reducing agent.

[0034] The preservative monomer used is:

[0035]

[0036] The procedure of Examples 2-8 was the same as Example 1, and the reagents and conditions parameters used were as follows:

[0037] Table 1 Preparation of fungicidal monomers

[0038]

[0039] Table 2 Preparation of polycarboxylic acid water reducer

[0040]

[0041] The preservative monomer used in Example 2 was:

[0042]

[0043] The preservative monomer used in Example 3 was:

[0044]

[0045] The preservative monomer used in Example 4 was:

[0046]

[0047] The preservative monomer used in Example 5 was:

[0048]

[0049] The preservative monomer used in Example 6 was:

[0050]

[0051] The preservative monomer used in Example 7 was:

[0052]

[0053] The preservative monomer used in Example 8 was:

[0054]

[0055] Comparative Example 1

[0056] Unlike Example 1, thiazole was used instead of the fungicidal monomer of Example 1.

[0057] Comparative Example 2

[0058] Unlike Example 1, benzyl ester was used instead of the preservative monomer of Example 1.

[0059] The bacteriostatic activity of the prepared sample was determined by filter paper method. Staphylococcus aureus, Bacillus subtilis and Escherichia coli were used as test objects in the experiment process, which were purchased from Shanghai Center for Bio-Organism Preservation. The specific test method was as follows: Staphylococcus aureus, Bacillus subtilis and Escherichia coli were activated in advance, and then were mixed with sterile water to prepare a bacterial suspension. Then, the bacterial suspension was mixed with beef extract peptone culture medium (peptone 1%, beef extract 0.3%, NaCl 0.5%, glucose 1%, pH 6.5-7) uniformly, and 5 mL of the mixture was taken in a 9 mm diameter culture dish. 5 μL of preservative with a concentration of 1000 μg / mL of polycarboxylate superplasticizer was coated on a 5 mm filter paper sheet, and dried. Each group had 3 parallel experiments. The dried filter paper sheet was placed on the surface of the culture medium, and was pressed by sterile forceps. Then, the filter paper sheet was cultured in a 30°C incubator for 18 h. The diameter of the bacteriostatic circle was measured by cross method, and the transparency of the bacteriostatic circle was observed. The test results are shown in Table 3.

[0060] Table 3 Bacteriostatic activity test of preservative

[0061]

[0062] “+” represents the degree of bacteriostatic circle, and the more, the more obvious the bacteriostasis.

[0063] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that, for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An antiseptic for polycarboxylate water-reducing agent containing organic bromine, characterized by, The preservative monomer is an organic bromine, and its structural formula is as follows: wherein M is one of the following: and a method for preparing the modified isothiazolinone, comprising the following steps in parts by weight: Step (1), 4-6 parts of isothiazolinone compound, 5-7 parts of acid anhydride are added into a four-necked flask with stirring device, thermometer and condenser tube, 100-180 parts of dimethylbenzene is put in under nitrogen protection, slowly heated, and reacted for 6-8 hours to obtain a crude product; Step (2), the obtained crude product is ground and washed with 30-50 parts of dimethylbenzene for 3-5 times, and then vacuum dried to obtain modified isothiazolinone.

2. The preservative for polycarboxylate water reducer containing organic bromine according to claim 1, characterized in that, The stabilizer is at least one of propylene glycol, propylene glycol fatty acid ester, D-mannitol, propylene glycol alginate, chitin or polyglycerol ricinoleate.

3. The preservative for polycarboxylate water reducer containing organic bromine according to claim 1, characterized in that, The structural formula of the isothiazolinone is as follows: R is one of H, Ph, Bn, Et and Me.

4. The preservative for polycarboxylate water reducer containing organic bromine according to claim 1, characterized in that, The acid anhydride is any one of maleic anhydride, phthalic anhydride and oxalic anhydride.

5. The preservative for polycarboxylate water reducer containing organic bromine according to claim 1, characterized in that, In step (1), the temperature is slowly increased to 100-150 DEG C.

6. The preservative for polycarboxylate water reducer containing organic bromine according to claim 1, characterized in that, In step (2), the vacuum drying time is 18-36 hours.

7. A method for producing the preservative for polycarboxylate water reducer containing organic bromine according to any one of claims 1 to 6, characterized by, The following steps are included by weight fraction: Step (1), the preservative monomer and the bactericidal monomer are added into 10-30 parts of water by weight, stirred uniformly to obtain a mixture; Step (2), the stabilizer is added into the mixture, the remaining water is added, and stirred for 10-30 minutes to obtain the preservative for polycarboxylic acid water reducer.

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